Study On Separation And Purification Of Taurine In Sodium Aqueous Solution

Taurine is a naturally occurring β-sulphonated amino acid that is not incorporated into proteins, but found in some simple peptides. To date, it is generally produced by use of the esterification and sulfonation of ethanolamine. However, this method will generate such byproduct as sulfate which can greatly affect the yield and purity of taurine. Different from the currently used hydrochloric acid-ethanol method, the crystallization separation method has been developed in this work basing on the phase diagram of the ternary system Na2SO4-H2NCH2CH2SO3H-H2 O. The main content of the thesis includes:1. The solid-liquid phase equilibria of the system Na2SO4-H2NCH2CH2SO3H-H2 O from 15oC to 80oC was experimentally studied by isothermal solution saturation method; and the phase diagrams were plotted as well.2. Based on the above phase diagrams, crystallization was employed to separate H2NCH2CH2SO3 H and Na2SO4. The yield and the purity of taurine can reach 77.05% and 95.12%, respectively, and thus the removal rate of Na2SO4 is 63.4%.3. The solubility of taurine in water was measured by titration method in the temperature range from 0 to 80oC. The experimental data were correlated with modified Apelblat equation. The metastable zone of Taurine was measured by using laser pen under different conditions.4. The recrystallization of raw taurine obtained was conducted by cooling crystallization, and the timetable can be concluded as: end temperature 15oC, agitating rate 300rpm/min, cooling rate 0.2°C ? min-1, and the amount of seeds 3% with size of 75-90 μm.The study will provide an important theoretical basis for the separation of H2NCH2CH2SO3 H from its sodium sulfate aqueous solution.